Fork lift attachment



Dec. 10, 1968 c. M. RANGE FORK LIFT ATTACHMENT 4 Sheets-Sheet 1 Filed April 18, 1967 CLYDE M. RANGE mvsmoa BY I E W, r

AT TORNEXS Dec. 10, 1968 c. M. RANGE 3,415,339

FORK LIFT ATTACHMENT Filed April 18, 1967 4 Sheets-Sheet CLYDE M. RANGE INVENTOR.

ATTORNEYS Dec. 10, 1968 c. M. RANGE FORK LIFT ATTACHMENT 4 Sheets-Sheet 3 Filed April 18, 1967 m ol GLYUE M. RANGE INVENTOR.

ATTORNEYS Dec. 10, 1968 c. M. RANGE FORK LIFT ATTACHMENT 4 Sheets-Sheet 4 Filed April 18, 1967 CLYDE M. RANGE INVENTOR.

ATTORNE Y5 United States Patent 0 M 3,415,339 FGRK LIFT ATTACHMENT Clyde M. Range, Rte. 1, Box 257, ()rovillc, Wash. 98844 Continuation-impart of application Ser. No. 588,039, Oct. 20, 1966. This application Apr. 18, 1967, Ser. No. 631,722

14 Claims. (Cl. 1822) ABSTRACT OF THE DISCLGSURE An attachment for dirigible vehicles known as fork lifts which include a rigid upright mast or frame, a second guide frame mounted for vertical telescoping movement on the first frame and an elevator carriage which is mounted for vertical movement on the second guide frame. The attachment comprises a boom having one end pivotally connected to the upper end of the vertically telescoping guide frame with the opposite end of the boom being adapted to be connected to a load. A secondary frame structure is pivotally connected to the horizontally extending tines of the elevator carriage and pivotally connected to an intermediate portion of the boom whereby the boom may be swung about its pivotal connection to the secondary frame by vertical movement of the elevator carriage and the entire attachment, as well as the elevator carriage, may be vertically raised thereby vastly increasing the vertical reach of the boom. The boom may be extended forwardly from the fork lift vehicle or may be so mounted as to extend laterally therefrom according to a second embodiment.

Background 0 the invention This is a continuation in part of my copending US. patent application, Ser. No. 588,039, filed Oct. '20, 1966.

The present invention relates to an attachment for dirigible vehicles of the type known as fork lifts, which include a vertically movable elevator carriage with generally horizontally extending fork arms or tines mounted on a vertically extendable telescoping frame. More particularly, the present invention relates to a device which may be detachably connected to a vehicle of the character described in a quick and efiicient manner and which provides a load-supporting and vertically movable extension for mounting a load-receiving platform or the like.

Although load-supporting extensions and attachments for fork lifts have been devised in the past, the present invention seeks to provide a new and improved load platform attachment or other loading member which may be more easily mounted and demounted from the fork lift and which, by reason of its manner of attachment, has an increased vertical reach. The present invention provides an attachment which requires little or no alteration of the basic structure of the fork lift vehicle. The present invention is also adapted for use with any conventional fork lift and will smoothly and efficiently raise and lower a load-supporting platform to an extended height above the fork lift, while maintaining the platform in a level position.

Accordingly, the object of the present invention is to provide an improved fork lift attachment for conventional fork lifts which requires little or no alteration to the basic fork lift structure for its mounting, which may be more easily and quickly mounted and demounted from the fork lift than prior art devices, and which has an increased vertical reach by reason of its manner of attachment.

Another object of the present invention is to provide an improved fork lift attachment of the character described which enables a load-sustaining platform to be 3,415,339 V Patented Dec. 10, 1968 raised and lowered smoothly and efficiently and maintained in a level position.

A still further object of the present invention is to provide a platform attachment for the fork lift of the character described which provides a simplified and yet sturdy structural arrangement.

This and other objects of advantages of the invention will be apparent from the following specifications and claims and from the accompanying drawings wherein:

Description of the drawings FIG. 1 is a perspective view of a dirigible fork lift vehicle with the attachment of the present invention mounted thereon;

FIG. 2 is a cross-sectional view taken along the lines 2--2 of FIG. 3;

FIG. 3 is a cross-sectional view taken along the lines 3-3 of FIG. 1;

FIG. 4 is an elevational detail of the pivotal connection between the fork lift and the boom portion of the attachment';

FIG. 5 is a schematic illustration showing the relationship between the fork lift and the attachment with the load-supporting platform in the lowered position;

FIG. 6 is a schematic illustration of the relationship between the fork lift and the attachment with the loadsupporting platform in the elevated position;

FIG. 7 is a perspective view of a modified form of the attachment;

FIG. 8 is a top plan view of the pivotal connection of the boom of the embodiment of FIG. 7;

FIG. 9 is a perspective view of a second modified form of the invention; and

FIGS. 10-12 are schematic illustrations of various positions of the attachment shown in FIG. 9.

Description of preferred embodiments Referring now to the drawings wherein like reference numerals indicate identical parts in the various views one form of the invention is shown in FIGS. 1-6 and includes a self-propelled dirigible vehicle 1 which may be of any conventional type well-known to the art having forward ground wheels 2 and the rear ground wheels 3 which are steered by an operator through the steering mechanism 4. The elevator portion of the vehicle 1 is indicated generally at 5 and, as will be well understood by those familiar with the art, includes a rigid upright guide frame or mast 6 fixed to the frame of the vehicle and, in the present illustration, braced by means of the overhead frame 7. As is conventional, the rigid guide frame 6 mounts a vertically telescoping second guide frame 8 which may be raised and lowered relative to the frame 6 by means of a hydraulic jack having a cylinder 9 secured to the frame 6 and a piston rod 11 connected to the top end of the frame as at 12. A conventional elevator carriage is indicated generally at 13 and is movably mounted on the frame 8 for vertical movement relative thereto. The elevator carriage 13 may be mounted for vertical reciprocation by means of chains, cables or the like in any known manner the details of which form no part of this invention. Rigidly mounted on the carriage 13 are vertical lift arms 14, both of which include the generally horizontally extending tines or lift arms 16-. The tines in normal use of the device constitute the load-supporting portion of the fork lift. Thus, a load resting on the tines or lift arms 16 may be raised and lowered relative to the frame 8 and the entire frame 8 and elevator carriage 13 may be raised and lowered relative to the stationary frame 6.

The attachment of the present invention comprises a boom indicated generally at 17 which, in the present illustration, comprises a rigid frame made up of the laterally spaced trussed beam structures 18. The beam structures 18 are provided with laterally projecting pivot pins 19 at one end for connection to the upper end of the frame 8 in a manner to be described and with laterally spaced brackets 21 on their opposite ends for receiving the pivot pins 22 of the platform indicated generally at 23. The pivotal mounting of the platform 23 allows the platform to swing relative to the boom 17 to maintain a level horizontal position as the boom is raised and lowered. The platform 23 may be varied in construction but will usually include a frame 24 to which the pins 22 are connected, vertical members 26 and some sort of floor or deck 27. The platform 23 is not limited as to use and may be used to carry personnel or cargo or both.

Referring to FIG. 4 in particular, the upper end of the extensible frame 8 is provided with a connector plate 28 on each side thereof which may be welded, bolted or otherwise attached in a fixed position to provide a pivotal axis for the boom 17. Each plate 28 is slotted upwardly from its bottom edge as at 29 for the purpose of receiving the pivot pins 19. The slot 29 may be widened at the bottom edge of the plate 28 in order to facilitate entry of the pins 19 as illustrated in FIG. 4.

A secondary frame structure 31 is pivotally connected between the boom 17 and the elevator carriage 13 and comprises the lateral spaced side frame members 32 with suitable cross bracings 33 and 34 serving to rigidify the structure. The upper ends of the members 32 are pivotally connected to the trussed beams 18 respectively as at 36 by any suitable arrangement such as that illustrated in FIG. 3. The lower end of each of the members 32 is pivotally connected to a base structure indicated generally at 37 which is removably mounted on the tines or horizontal lift arms of the elevator carriage. The base structure 37 may comprise a cross beam 38 having brackets 39 secured thereto for pivotally connecting the bottom ends of the frame members 32 by means of pins 41 as shown in detail in FIG. 2.

In order to mount the base member 37 on the tines of the fork lift, the cross beam 38 is provided with shoes 42 which telescopically receive the tines 16 through suitable openings 43 therein. The shoes 42 may be made slidable on the cross member 38 as illustrated in order to accommodate the spacing of the tines of any given fork lift. In the alternative, the member 38 could be provided with several rigidly attached shoes on each end in order to adapt the base for attachment to any fork lift. With the present arrangement, the boom 17 obtains vertical support through the secondary frame 31 with the plates 28 engaging the pivot pins 19 to prevent rotation of the beam. In addition, a link 44 is connected between the bottom of the platfrom 23 and the upper portion of the secondary frame 31. The link 44 is pivoted to the frame 31 at 46 and to the platform at 47 and extends substantially parallel to the portion of the boom 17 between the pivot points 36 and 22 so as to form a parallelogram structure. Thus, as illustrated in FIGS. and 6, the platform 23 is maintained in a level position as the boom 17 is rotated about the pins 19 as the elevator carriage 13 is moved upwardly on the frame 8. The members 32 are also provided with outwardly projecting arms 48 having pads 49 for receiving the frames 18 when the attachment is in the extreme lowered position shown in FIG. 5.

The attachment is provided with means for forming a second platform in cooperation with the tines 16. To this end a plate or panel 50 is pivotally attached as at 51 to suitable brackets on the cross beam 38. The panel 50 may be swung from a generally vertical position of non use as shown in FIG. 5 to a use position wherein it is supported by tines 16 as shown in FIGS. 1, 2 and 6. The member 50 may be made of heavy gauge sheet metal or other material and may be provided with members 52 which directly engage the tines. The platform provided by the member 50 may be utilized to carry such items as tools or equipment for example such that the attachment need not be raised and lowered for such items during a particular use. As an example, Welding equipment and accessories could be mounted on the member 50. The ladders 53 and 54 carried by the boom 17 and frame 31 respectively may be used to move back and forth between platfrom 23 and the platform provided by panel 50 when the attachment is in the raised position.

In order to mount the attachment on the fork lift vehicle l, the vehicle is moved forwardly so as to insert the tines 16 within the shoes 42 and the pins 19 are engaged in the slots 29 of the plates 28, the frame 8 being in the lowered position. Once the shoes are engaged and the pivot pins 19 located in place, the elevator carriage 13 may be raised to pivot the boom 17 about the axis formed by the pins. In the event that increased vertical reach is desired for the boom the guide frame 8 may be raised relative to the mast 6 as shown in FIG. 6. The elevator carriage 13 may, of course, be raised and lowered to rotate the boom regardless of the position of the frame 8 thus providing a wide range of maneuverability. In order to detach the structure, the frame 8 is lowered and the elevator carriage 6 is lowered so that the pins 19 may be removed from the slots 29 and the vehicle backed away from the attachment.

FIGS. 7 and 8 illustrate a second form of the invention wherein the load supporting boom is mounted so as to extend laterally from the fork lift rather than forwardly or longitudinally as in the first embodimentv It will be understood that the fork lift vehicle may be identical to that described with relation to FIGS. 1 through 6 and has been eliminated from FIG. 7 for sake of simplicity. As previously described, the fork lift vehicle includes the rigid vertical mast 55, vertically extensible guide frame 57 in telescoping relation with mast 55 and an elevator carriage indicated generally at 58. The frame 57 is raised and lowered by means of the ram 59 and the elevator carriage 58 may be raised and lowered by conventional means such as lift chains, cables or the like not shown. The elevator carriage 58 is provided with conventional horizontally extending tines or lift arms 61 and 62 and the upper end of the frame 57 is provided with connector plates 63 which may be identical in all respects to the previously described plates 28 of the first embodiment. Plates 63 are slotted as at 64 for the purpose of receiving pivot pins for the boom as will presently be described.

The boom, indicated generally at 66 may be similar in structure to the boom 17 of the previous embodiment in that it is made up of trussed beam structures 67 connected in any suitable fashion to provide a rigid boom. The outer end of the boom 66 is pivotally connected as at 68 to the platform 69. The other end of the boom 66 is formed in a generally triangular configuration in plan as shown in FIG. 8 with the structural members 71 and 72 being connected between one trussed beam 67 and the other so as to be joined at sleeve 73. The sleeve 73 engages a stub shaft 74 which is fixed to a cross arm 76 which has pivot pins 77 provided on its opposite ends for engaging the slots 64 in the plates 63. With this arrangement, the boom 66 can pivot about the axis of shaft 74 and the pins 77 serve to retain the cross arm 76 in place which the boom is raised and lowered. The boom is raised and lowered by means of the secondary frame 78 which includes lateral upright frame members 79 and 81. The members 79' and 81 have their opposite ends connected respectively to the boom as at 82 and 83 and to a shoe member 84 as at 86 and 87 respectively. The shoe member 84 may be a rectangular cross section channel of a suitable dimension for telescoping over one of the tines 62 as illustrated. In order to maintain the platform 69 in a level horizontal position during raising and lowering the connector link 88 is pivotally connected between the floor of the platform and the secondary frame member 78 in order to form a parallelogram as illustrated. The boom 66 pivots in a vertical plane much in the same manner as described in the previous embodiment except that the pivotal axis is about the longitudinal axis of the shaft 74. The boom will move in a transverse vertical plane with raising and lowering of the elevator carriage 58 with respect to the guide frame 57. The increased vertical reach is obtained by telescoping the guide frame 57 relative to the mast 55 as previously described. It will also be understood that the embodiment shown in FIGS. 7 and 8 may be provided with ladders such as shown in FIGS. 1 and 3.

FIGS. 9 through 12 show still another embodiment of the invention wherein the boom is utilized as a load lifting boom and is so connected to the extensible guide frame as to be pivotable through a greater arc than that possible with the previous embodiment. The boom structure in this modification may be pivoted to a substantially vertical position if desired. Referring to FIG. 9, the mast 89, vertically telescoping guide frame 91, lifting ram 92 and elevator carriage 93 are conventional and may be identical to those previously described. The horizontal tines or lifting forks are shown at 94 and it will be noted that the top end of the frame 91 is provided with bracket means 96 for pivotally connecting one end of the cylindrical boom member 97. The boom 97 may be provided with any appropriate means for reinforcing such as the truss members indicated generally at 98. The outer end of the boom 97 may be provided with a hook, ring or the like 99 suitable for attaching a load. The boom 97 is pivoted about the pin 101 by means of the secondary frame 102 which, in the present instance, is in the form of an A-frame having its upper end pivotally connected to an intermediate point on the boom by means of the pivot pins 103 as illustrated. The bottom ends of the A-frame leg members are pivot ally connected to the shoe members 104 which telescope onto the ends of the tines 94 of the fork lift. A stop member 106 is located at the upper end of the frame 102 so as to limit the downward pivoting of the boom to the lowered position as illustrated in FIG. 10. To complete the structure of the attachment, the shoes 104 are provided with chains 107 which are connected tothe shoes and to a portion of the elevator carriage 93 so as to limit the outward movement of the shoes relative to the tines to prevent the shoes from being removed during use. The rods 108 may be welded or otherwise rigidly connected to the shoes 104 and extend rearwardly along the top surface of the tines so as to limit the inward movement of the shoes 104 along the tines for the purpose presently to be described.

Referring now to FIGS. 10, 11 and 1 2, the various positions of the attachment are schematically illustrated. FIG. 10 illustrates the down or lowered position of the boom wherein the frame 102 is substantially vertical and the stop member 106 engages the boom to hold it in a rest position. FIG. 11 illustrates an intermediate position of the boom wherein the frame member 102 moves to an outwardly inclined position which would normally result in the shoes 104 being pushed inwardly on the tines. In this instance, the stops 108 limit the movement of the shoes. It will also be understood that the simple boom structure 98 could be extended laterally and pivotally about a longitudinal axis as in the modification shown in FIGS. 7-8. FIG. 12 illustrates the vertical or substantially vertical position of the boom with the guide frame 911 in its vertically extended position thereby giving the full vertical reach possible 'with the attachment. In this position it will be noted that the frame 102 is inwardly inclined in a direction opposite from that shown in FIG. 11. In this instance, the chains 107 prevent the shoes 104 from being forced off of the ends of the tines which would be the normal tendency upon upward movement of the elevator carriage to pivot the boom past a certain point.

From the foregoing, it will be apparent to those skilled in the art that the present invention provides new and useful improvements in fork lift attachments of the character described. The arrangement and types of structural components utilized in this invention may be subjected to numerous modifications well within the purview of this invention and applicant intends only to be limited to a liberal interpretation of the specification and appended claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In combination with a fork lift. truck of the type including a vehicle, an upright mast structure on said vehicle, an upright frame member, means mounting said upright frame member for vertical movement on the mast structure, an elevator carriage mounted for vertical movement on the upright member independently of the vertical movement of the upright member on the mast, and projecting load-supporting means fixed to said carriage; a boom, a second frame pivotally connected at one end to the boom intermediate the ends thereof, means pivotally connecting the other end of the second. frame to said load supporting means and means on one end of said boom andthe upper end of said upright frame member pivotally connecting the boom to the upright frame member.

2. The combination according to claim 1 wherein said boom is pivoted about a horizontal axis extending transversely to the longitudinal axis of the vehicle.

3. The combination according to claim 2 wherein said boom is pivotable between a position inclined downwardly below horizontal and a substantially vertical position.

4. The combination according to claim 3 wheren; said load-supporting means comprises laterally spaced tines, said means pivotally connecting the other end of the second frame comprising laterally spaced shoe members pivotally connected to the second frame and telescopingly receiving said tines, and means connected to said shoes and said load-supporting means for limiting the movement of the shoes relative to the tines during pivoting of the boom.

5. The combination according to claim 1 wherein said boom is pivoted about a horizontal axis extending parallel with the longitudinal axis of the vehicle.

6. The combination according to claim 5 wherein; said load-supporting means comprise laterally spaced tines, said means pivotally connecting the other end of the second frame comprising an elongated shoe member pivotally connected to said second frame and telescopingly engaging one of said tines.

7. The combination according to claim 5 wherein said boom is pivotable between a position inclined downwardly below horizontal and a substantially vertical position.

8. The combination according to claim 1 including; a load-supporting platform pivotally connected to the end of the boom, and link means pivotally connected between said platform and said frame to maintain said plotform in the level position during swinging movement of the boom.

9. The combination according to claim 8 including; a panel member pivotally connected to said base and adapted to swing from a substantially vertical position against said frame to a generally horizontal position to be supported on said load-supporting means.

10. The combination according to claim 1 wherein said means pivotally connecting the boom to the upright member comprises; a projection on each side of the upper end of the upright member, each projection having a slot opening into the bottom edge thereof, and pivot means on said boom adapted to engage said slots.

11. The combination according to claim 10 including; a load supporting platform pivotally connected to the other end of the boom, and link means pivotally connected between said platform and said frame to maintain said platform in the level position during swinging movement of the boom.

12. The combination according to claim 10 wherein; said projections comprise plate members fixed to the sides of the upright member, and said pivot means comprises laterally projecting pins fixed to the end of the boom.

13. The combination according to claim 12 wherein; said load-supporting means comprise laterally spaced tines, said means pivotally connecting the other end of the second frame comprising a base structure pivotally connected to said second frame and laterally spaced shoe 2,831,592 4/1958 Syracuse 214620 mer bers having openings therein for telescopingly re- 2 835 402 5/1958 E l m 214 620 ce1v1ngsa1dt1ne. 2,840,255 6/1958 Pollard 2146 0 14. The combmatlon accordmg to clalm 13 wherem 3 294 262 12/1966 Person id shoe members are adjustable on said base structur 5 n to accommodate the Spacing of Sald tlnes' REINALDO P. MACHADO, Primary Examiner.

References Cited U5, C1, X.R UNITED STATES PATENTS 214 620 2,672,377 3/1954 Werner 1822 10 

